HIV-based gene therapy effective for a lysosomal disorder

Scientists in France have used a disabled HIV virus to deliver corrected genetic code into the blood of X-linked adrenoleukodystrophy patients for the first time. Gene therapy, in which a patient's DNA is modified to correct genetic defects, has long been a holy grail of medicine, but it has been difficult in practice. To make gene therapy work, you have to replace the DNA in every cell that's affected. The problem with this is that the process of modifying all those cells too quickly can easily kill the patient. One mechanism for inserting new DNA is to use a modified virus [since a virus is little more than parasitic syringe for DNA], but with that route, it's important to control the rate at which the virus spreads. This is encouraging news, because if HIV proves a safe and effective carrier for new genetic material, it could be applicable to a range of diseases hypothetically treatable with gene therapy.